A pigtailed scotchcast assembly is utilized in those fields requiring either pre- or post-inspection of extended cavities, ducts or piping, such as but not limited to the sewer pipe relining industry. In such fields, it is typically necessary to inspect the condition of an extended cavity through the use of a plurality of electrical components. Cameras, lights, cutters and other components are utilized for this purpose and must each be supplied with electrical power to operate. As these cavities are either too confining, unsafe or otherwise unaccommodating for a human presence, the movement of electrical components along the length of any given cavity must be performed by mechanical means. A pigtailed scotchcast assembly is therefore enlisted to provide electrical power to the various components utilized, while also assisting in pulling such components and their associated electrical wiring through the cavity itself.
As is currently known and depicted in prior art FIG. 1, a typical pigtailed scotchcast assembly 10 is comprised of a scotchcast 12 having an electrical cable 14 entering one end thereof and a plurality of pigtails 16 exiting the opposing end of the scotchcast 12. The scotchcast 12 includes a pair of wings 18 each having an anchor hole 20 formed therein for dragging or pulling the pigtailed scotchcast assembly 10 along a cavity or piping. The electrical cable 14 is separated into differing bundles of conductors inside the body of the scotchcast 12 and subsequently emerges from the scotchcast 12 as pigtails 16. The interior of the scotchcast 12 is filled with a resin and catalyst compound which, when sufficiently dried and cured over time, provides a watertight sealant to the scotchcast 12 and the wire bundles therein.
As will be readily appreciated, when the pigtailed scotchcast assembly 10 is dragged or pulled through many cavities or pipes, the pigtails 16, including the protective sheathing covering the pigtails 16, tend to wear and become tattered, leading to operational failure of the supported electrical components. In these instances, inspection of the cavity or piping must be halted while the entire scotchcast assembly 10 is severed from the electrical cable 14 and another assembly attached in its place. This method is time-consuming, costly, requires expertise in electronics and must frequently accommodate the recommended 12-hour time period that a typical insulating and waterproofing resin and catalyst compound requires to cure.
Another known pigtailed scotchcast assembly 30 is shown in FIG. 2 and was the subject of commonly assigned U.S. Pat. No. 6,250,955, herein incorporated by reference in its entirety. As shown in FIG. 2, the two-piece pigtailed scotchcast assembly 30 is comprised of a first portion 32 capable of integrally and selectively mating with a second portion 34. The first portion 32 includes a central housing 35 from which a plurality of pigtails 36 are adapted to extend. The pigtails 36 each contain a varying number of electrical conductors and terminate in a connection end 38 for connection with various electrical components.
Still in reference to FIG. 2, the second portion 34 includes a threaded connection piece 46 having a female attachment end 48 and a connecting tip 50. The female attachment end 48 has exterior threads formed on the outer circumference thereof and further includes a plurality of pin receptacles 52. The pin receptacles 52 are arranged in number and orientation so as to match and integrally mate with the connection pins 42 of the male attachment end 40. The male and female attachment ends 40 and 48 respectively, are brought into watertight contact with one another as the threads of the female attachment end 48 are selectively engaged with the inner threads of the operation ring 44.
The connecting tip 50 is equipped with a plurality of outwardly extending female posts 56 which are each utilized to anchor the individual conductors of an electrical cable 58 through a known soldering or crimping process, or the like.
Moreover, as shown in FIG. 2, a scotchcast 60 is employed through which the electrical cable 58 is fed. The scotchcast 60 is adapted to include a first mating end 62 and a second mating end 64. An end plug 66 is slidable along the electrical cable 58 and includes a first plug end 65 and a second plug end 67 wherein the first plug end 65 threadedly engages a second mating end of the scotchcast 64. A seal 68 is also slidably mounted about the electrical cable 58 and provides a watertight barrier when properly seated between the second plug end 67 and the electrical cable 58. An end cap 70 is slidably mounted about the electrical cable 58 and includes threads formed about the inner periphery thereof so as to threadedly engage with the second plug end 67.
A cut-out 61 is schematically shown in FIG. 2 to reveal a clamp 80 located within the housing of the scotchcast 60 and centered about the electrical cable 58. The clamp 80 is formed from a wear resistant material, such as metal or the like, and is held to the electrical cable 58 in a non-slidable fashion, through friction, in any of a number of conventional manners. When the end plug 66 is fully engaged with the second mating end 64, the electrical cable 58 is prohibited from being pulled free of the scotchcast 60 by the abutment between the clamp 80 and an end face 81 of the first plug end 65. The clamp 80 therefore greatly increases the pulling capacity of the scotchcast 60.
As also depicted in FIG. 2, a tension web 90 extends along the length of the electrical cable 58 and provides additional pulling capacity to the scotchcast 60. The tension web 90 is typically formed from a weave of metal, nylon or other resilient material and serves to tighten about the electrical cable 58 in proportion to the pull exerted upon the tension web 90. When utilized as a whole, the clamp 80 and the tension web 90 allow the scotchcast 60 to withstand stresses up to approximately 5000 lbs. of pulling capacity without endangering the integrity of the electrical cable 158.
While effective, it will be readily appreciated that much time and great care had to be employed in order to solder each individual terminal end of the conductors in the electrical cable 58 to the posts 56, as shown in FIG. 2. Moreover, once accomplished, these fixed and soldered connections may actually become an impediment should an operator wish to adapt the wiring schematic of the electrical cable 58 to a new application.
In addition, the clamp 80 was found to occupy a significant amount of room within the scotchcast 60 while providing only a measured increase to the pulling capacity of the scotchcast assembly 30. Moreover, the tension web 90 performed well until becoming caught or snagged upon a foreign object which, in turn, would cause the tension web 90 to bunch up and therefore lose much of its pulling capacity.
With the foregoing problems and concerns in mind, it would therefore be advantageous to develop a pigtailed scotchcast assembly, which overcomes the above-described drawbacks, thereby accommodating a quick and efficient adaptation of a differing wiring schematic and increased pulling capacity.